Origins of Adventure
by The Cowardly Christian
Summary: Major AU. Who were Marceline's parents? why did the Mushroom war happen? How was the Enchiredion created? Where did the Cosmic owl come from? And how did a certain town in Oregon get involved in this? Finn and Jake are going to...find some of these answers...hopefully? Anyway, it's MYSTERY TIME! A story idea given by 'Dr-Indigo'.
1. Chapter 1

**Origins of Adventure**

I OWN AND REGRET NOTHING!

...

 **AN: This was a story idea of 'Dr-Indigo'**

...

 **ANNOUNCEMENT!**

 **I'M GETTING A BOOK PUBLISHED!**

 **SUMMARY:**  
 **On the 13th day of the 13th month of the 13th year...magic will return to the world...and the streets will run red with the blood of the (semi)innocent...unless the world is saved by the most unlikely of hero's...baking cupcakes?!**

 **The title is '13/13/13' and it'll be coming to a bookstore or E-Book site near you! Xilbris is the publisher, also available at Amazon, Inkitt and BarnesandNoble.**

...

Finn and Jake were doing their usual thing; traveling to distant lands, making new friends, singing jaunty tunes-

 **ROAR!**

-And killing monsters of course!

The swamp ogre/hydra/lion screamed as Finn cut of it's tentacle! The beast smacked Finn and sent him flying. Jack would've caught him, but he was too busy keeping himself from getting eaten inside one of it's many pincers...

 **CRASH!**

Finn groaned as he picked himself up, his muscles ached under the debris of the wall he just smashed through. Finn reached out and grabbed something for support-

 **Click.**

 **-bzzt- confirmation confirmed -bzzt- Oregon -bzzt- Gravity Falls -Bzzt- Target -bzzt- Anomaly -bzzt-**

Finn's eye's widen at the sight of another human! Or rather...the hologram of another human. He was dressed sorta like Cournel Candy corn, so Finn figured he had to be a big-shot millitary guy.

Finn looked around...it looked like he was in some kind of war room...or what USED to be a war room anyway...

 **-bzzt- confirmation confirmed -bzzt- Oregon -bzzt- Gravity Falls -Bzzt- Target -bzzt- Anomaly -bzzt-**

The hologram seemed to be some kind of recorded message stuck on repeat...but it was too corrupted to really understand...

FINN! BUDDY! COULD USE SOME HELP HERE!

The shouts of his brother reminded him of more pressing matters, still he remembered P.B's love of all pre-mushroom war tech so he used one of the flash drives she'd given him to quickly download the message and any other info the place had onto it. He then screams like a loon toward the monster, sword proudly drawn.

...Not realizing he'd stumbled upon the secrets of the origins of his world as he knew it...

...

TO BE CONTINUED?

 **AN: I know it says "in-progress" but really I just don't like boxing myself into a corner. For now this is more of a one-shot that I might continue one day...but probably won't.**  
 **But, hey. Feel free to use whatever elements you want from this, if you want! Or maybe give me ideas?**

 **Love me, flame me, review me**


	2. Chapter 2

**Origins of Adventure 2**

I OWN AND REGRET NOTHING!

...III...

 **ANNOUNCEMENT!**

 **I'M GETTING A BOOK PUBLISHED!**

 **SUMMARY:**  
 **On the 13th day of the 13th month of the 13th year...magic will return to the world...and the streets will run red with the blood of the (semi)innocent...unless the world is saved by the most unlikely of hero's...baking cupcakes?!**

 **The title is '13/13/13' and it'll be coming to a bookstore or E-Book site near you! Xilbris is the publisher, also available at Amazon, Inkitt and BarnesandNoble.**

...III...

PB examined the data with interest. "Peculiar...according to this the 'USSSAA'- She experiments with the odd word with her tongue, unsure how to pronounce it right -government detected an unknown energy source in the form of a giant bubble deep inside their territory, it was effecting local reality...so natural in a panic they just blow it up." She read that last part while rolling her eyes.

"Sounds like a plan to me!" Shouts Jake excitedly while Finn nods in agreement.

PB sighed and continued, "By the looks of things not only did their... 'NuCleAr?' -Anyway, their attack not only made things worse by unleashing all the strange energies contained within to spread across the globe. But it caused all the other nations to panic and fire their weapons as well."

Finn's eye's went wide, "Wait, do you mean...?"

PB nodded excited, "Yes, Finn. I think you may have stumbled on the original cause of the Mushroom War! We must investigate this at once!" She pauses to add some data to her tracker.

"If I'm right...YES! The coordinates of the launch are still logged! By using that abandoned army instillation as a starting point we SHOULD be able to triangulate 'ground zero'."

Quickly they climb onto The Morrow and fly away...

"Goodbye Princess!" Shouts a Banana guard waving after them, "Boy! The origins of the Mushroom war! What a thing to occur a few days before my retirement!"

 **squick**

The banana guard looked down to see the blade protruding from his chest...the guard looks annoyed, "Dang it! I knew I should've asked for hazard pay!" His eyes then roll into his head as he drops down dead...

An unknown figure cloaked in darkness cleans his blade. He then looks in the direction the hero's had flown...and follows after them...

…III...

TO BE CONTINUED?

 **AN: I know it says "in-progress" but really I just don't like boxing myself into a corner. For now this is more of a one-shot that I might continue one day...but probably won't.**  
 **But, hey. Feel free to use whatever elements you want from this, if you want! Or maybe give me ideas?**

 **Love me, flame me, review me**


	3. Chapter 3

**Origins of Adventure 3**

I OWN AND REGRET NOTHING!

...III...

 **ANNOUNCEMENT!**

 **I'M GETTING A BOOK PUBLISHED!**

 **SUMMARY:**  
 **On the 13th day of the 13th month of the 13th year...magic will return to the world...and the streets will run red with the blood of the (semi)innocent...unless the world is saved by the most unlikely of hero's...baking cupcakes?!**

 **The title is '13/13/13' and it'll be coming to a bookstore or E-Book site near you! Xilbris is the publisher, also available at Amazon, Inkitt and BarnesandNoble.**

...III...

A hologram of Ford Pines pops up-

 **To all who hear this, let it be recorded-**

 **BOOM!**

 **-that on the day 2012, August 31-**

 **BOOM!**

 **-that the world as we knew it-**

 **BOOM!**

 **-Came to an-**

 **BOOM!**

"GUYS! WILL YOU KEEP IT DOWN!? I CAN'T HEAR THE RECORDING!"

Shouts a frustrated Bubblegum as she tinkers with the SOS beacon that they'd found in the giant crater where the coordinates had led them...

"KINDA BUSY, RIGHT NOW!" Shouts Finn as he and Jake battle two giant, mutant monsters.

One was a giant fairy-like creature with hundreds of mouths that constantly vomited, the other seemed to be cross between a chubby green man and a giant unicorn with hundred of tentacles who was constantly screaming, "!ESAELP !EM LLIK !EM LLIK !ESAELP !EM LLIK !EM LLIK !ESAELP !EM LLIK !EM LLIK"

While they fought it off, Bubblegum tried to listen to the rest of the message...

Apparently a chaotic inter-dimensional entity named 'Bill Cipher' had tried to invade their dimension in a place called 'Gravity Falls'. Ford and his family eventually defeated him by trapping him in his twin brothers mindscape which he then erased...

Unfortunately, it was too late. 'Weirdmagedon' had come to the US governments attention and had proceeded to nuke it, doing so not only broke the weirdness bubble keeping most of Bill's weirdness from infecting the world but also gave Bill the opportunity to escape the mindscape.

Fortunately, it seems that Bill was too badly damaged and was on the verge of death...

But as one last 'frack you' to humanity he used the last of his strength to send his weirdness out to infect the world, thus bringing magic back into it...

The other nations of the word, panicked over all this and launched their own nukes at anything that seemed even remotely like a threat,,,which was everyone...

And thus began the mushroom war...and the end of humanity...

 **Me and my family and the rest of the survivors are leaving, the nuclear fallout has rendered this place uninhabitable. Fortunately, many years ago I put contingencies in place. To anyone that receives this...go to these coordinates; if we survive...we'll be at one of these places..."**

Bubblegum quickly copies the info...

She turns to the two boys still fighting the beasts, "I have what we came for! Let's go!" There was some interesting dimesional readings around here...but that would be a project for another day...

Before the boys could disengage however...

 **Ratta-Tatta-Ratta-tatta!**

They had to dodge a helicopter shooting at them-

 **BOOM!**

Which then blew up?

 **BOOM!**

 **BOOM!**

As did the creatures?

The three frinds looked to where the explosives had come from...and saw a small man wearing a red pointy hat and a biker jacket.

"Schmebulock."(1)...

…III...

TO BE CONTINUED?

 **1: "Come with me if you want to live..."**

 **AN: I know it says "in-progress" but really I just don't like boxing myself into a corner. For now this is more of a one-shot that I might continue one day...but probably won't.**  
 **But, hey. Feel free to use whatever elements you want from this, if you want! Or maybe give me ideas?**

 **Love me, flame me, review me**


	4. Chapter 4

**Origins of adventure 4**

I OWN AND REGRET NOTHING!

...III...

 **ANNOUNCEMENT!**

 **I'M GETTING A BOOK PUBLISHED!**

 **SUMMARY:**  
 **On the 13th day of the 13th month of the 13th year...magic will return to the world...and the streets will run red with the blood of the (semi)innocent...unless the world is saved by the most unlikely of hero's...baking cupcakes?!**

 **The title is '13/13/13' and it'll be coming to a bookstore or E-Book site near you! Xilbris is the publisher, also available at Amazon, Inkitt and BarnesandNoble.**

...III...

Bubblegum was more and more intrigued with the current situation, following the coordinates Ford left behind they'd been jumping from one potential hiding spot for the 'Gravity falls residents' to another...

The first was surprisingly where Mount Cragdor now stood. Manish Man explained how he was once part of the man-o-taur tribe...but his parents were killed during Weirdmagedon and Dipper Pines- apparently Ford's Nephew -adopted him.

Due to certain revelations- such as His sister being the cause of weirdmagedon -and how much the labs of this bunker had been 'altered' in a beneficial way by the weirdness of Weirdmagedon...Dipper had decided to stay when the others moved on to learn great secrets about the world, the universe, and those beyond, which he recorded in a journal that would later become known as the Enchirideon.

And he used what he learned to extend his lifespan by over five centuries. But eventually, he succumbs to old age. So I his final days, Dipper converted his home in Mount Cragdor into a proving ground for heroes, and entrusted his adopted son Manish Man to guard his journal until it could be claimed by someone worthy.

They also learned that during his travels, Dipper heard a rumor that a cantankerous old shyster calling himself the King of Thieves was attempting to build his own city inside the shell of a giant turtle...his description matched that of his uncle Stan that supposedly died when Bill was freed... Regrettably, he never made much of an effort to see if these rumors were true. So who knows what happened there?

Afterwards they went to the next set of coordinates which surprisingly turned out to be around Billy's tribe. Canyon was there and told them that apparently Ford was also mutated after the nuclear strike, but in his case it only turned his skin dark blue.

Many years later, he came to one of his many bunker's mumbling about escaping a 'calamity' but would never go into more detail then that. He met up with a group of Jotun or Frost Giants who had left their home dimension to start a new colony on Earth near his bunker.

Because of his appearance, they accepted him into their group and overt time he even took a wife. As an added bonus of his mutation, Ford's lifespan was greatly extended and he was able to spend his last 97 years living happily with his with Ingrid and their son Billy.

They then learned that another Bunker had been co-opted and taken over by an old colleague of Ford...Moseph Mastro Giovanni, or Moe for short.

Who had fled there during the war. Several years after the war, a Gravity Falls resident named Candy had wandered in to see if there were any supplies in the supposedly abandoned Bunker. Her parents having died during Weirdmagedon, she stayed after the others went back to 'New Gravity Falls' being interested in the inventors study in robotics.

The two of them worked closely together on the first generation of MO's, and she even allowed her mentor to duplicate her brainwaves and implant them in a very special MO. Unfortunately, she wasn't as in to prolonging her life as Moe was, so she succumbed to old age a LONG time before he did.

Indeed Bubblegum couldn't help be fascinated by all these secrets being uncovered, she wondered-

 **BOOM!**

And just like that Morrow was dead...and she was falling from the sky...

…III...

TO BE CONTINUED?

 **AN: I know it says "in-progress" but really I just don't like boxing myself into a corner. For now this is more of a one-shot that I might continue one day...but probably won't.**  
 **But, hey. Feel free to use whatever elements you want from this, if you want! Or maybe give me ideas?**

 **Love me, flame me, review me**


	5. Chapter 5

**Origins of adventure**

I OWN AND REGRET NOTHING!

...III...

 **ANNOUNCEMENT!**

 **I'M GETTING A BOOK PUBLISHED!**

 **SUMMARY:**  
 **On the 13th day of the 13th month of the 13th year...magic will return to the world...and the streets will run red with the blood of the (semi)innocent...unless the world is saved by the most unlikely of hero's...baking cupcakes?!**

 **The title is '13/13/13' and it'll be coming to a bookstore or E-Book site near you! Xilbris is the publisher, also available at Amazon, Inkitt and BarnesandNoble.**

...III...

 ** _BANG!_**

 ** _WENDY!_**

 _Mable, get out of there!  
_

 ** _ROAR!_**

...

Bubblegum awoke in a cold sweat and a ringing pain in most of her body, she looks up to see...Finn fighting another helicopter ridding Stormo?

"Wait, Stormo? But he's supposed to be-

 **BOOM!**

"...Fighting Goliad." Bubblegum trails off as she watches Schmebulock do battle with her heir/candy Sphinx nearby. Too weak and injured to lend aid, PB slinks toward a nearby structure...

...

 _ **GAH!**_

 _Neddy screamed as he fell from the mother gum and landed on jagged rocks, he then fled screaming in agony. A newlyborn PB ran after him in concern..._

 _..._

PB's eye's widen as the memory goes through her head, the mother gum! This candy factory was her long lost birthing site! Her memory cortex hadn't fully developed back then, which had left some gaps...

She knew she was in danger currently, but surely she had enough time to-

 **REEEEEE!**

Bubblegum felt her blood go cold as the sound of a fellow gum creature in agony. She quickly ran inside-

 **REEEEEEE!**

Just in time to see more blacksuited men gun down a gum creature! "Right, that should be the last of the them! This place has been compromised! Burn the remains and blow the place sky-high!" Shouted the apparent commanding officer.

Fearful, Bubblegum ran to the center room...and broke down in sobbing...

The mother gum...her mother, father and family...was dead. She sobbed as she hugged it's remains...and glared at would-be-familicide. She picked up what little remianed...wrpped some old fabric around her face like mask...and went in the hunt...

...

"Soooo...explain to me again why the boss wants random pieces of ancient history destroyed/covered-up?" Asked a blacksuited man to his partner. His partner groaned, "For the love of...stop playing that dang snappy bird and listen to meetings! Look it's REALLY simple, the reason were ereasing all evidence of 'gravity falls' is-

 **BAM!**

And then the catwalk feel on them, killing them instantly...

...

two guards secure the perimeter-

 **POW!**

Only to be made into Swiss cheese by an explosion of nails and rivets...

...

Several guards are throwing the remains of dead gum into an incinerator-

 **CRUNCH!**

Only to get impaled on a jury-rigged remote controlled forklift...

...

"Team 5? Team 12? Team Uno? SOMEONE ANSWER ME!" Shouted team leader. Panicked he ran out of the factory on his own-

 **GAH!**

Only for him to end up dangling upside down thanks to a snare...followed by his arms, making him go spread-eagle.

He looks down and sees PB, hand over a button. "Wait! Let's not be hasty! I have connections! And valuable swag! Tell me what you want and I'll get it! Name your price!"

PB glared defiantly. "I want my family alive and well." She stated simply and pressed the button.

 **GAH!**

 **SQUICK!**

PB sighed at the blood that had been spattered all over her, she takes the cloth she'd wrapped around her face to wipe it off...and then she sees the cloth is no cloth...it's an old, bedazzled, colorful sweater...so...so familiar...

And then it came to her...the memories...

Gnomes.

Multi-bears.

Summerween Tricksters!

Oh, my!

PB remembered now...she is...or WAS Mable Pines...a bright, quirky, lovely girl...who let her selflessness toward her brother destroy the world.

Apparently she caused Weirdmagedon, after they left gravity Falls Dipper found out...he refused to be with Mable anymore...but despite everything he still loved her enough to not blow her secret. So he simply left to travel the world without telling anyone WHY.

...Mable was devastated...that's why when she and Wendy were on a foraging trip...she deliberately awoke some Goo zombies...hoping they'd kill her...they somewhat succeeded...her body was torn apart and thrown into the candy factory.

Between the damage and radiation she was going to die...but not before what remained of her was assimilated by the mother gum...and eventually her DNA would be used to make PB.

...

PB was stunned by this revelation...but decided to wonder what this could mean later, she now had the location for 'New' Gravity Falls. The final stop, the monsters murdered her family to keep it secret...now she would find out WHY...

What started as a simple quest...had now become PERSONAL...

…III...

TO BE CONTINUED?

 **AN: I know it says "in-progress" but really I just don't like boxing myself into a corner. For now this is more of a one-shot that I might continue one day...but probably won't.**  
 **But, hey. Feel free to use whatever elements you want from this, if you want! Or maybe give me ideas?**

 **Love me, flame me, review me**


End file.
